What happens if the PSU is not enough for a system with a graphics card?

What exactly will happen if I use a PSU that is not enough for the system + a graphics card?

Does the PSU get destroyed or the components that is powered by the PSU and the PSU itself gets destroyed?

The system I am using has 300W and I want to add a 750 Ti without upgrade the PSU so I want to know the risks.

 

You'll get a ton of instant crashes (as in total hardware failure where the computer just shuts down), as well as blue screens. After that happens a few times you'll fry your motherboard, graphics card, and probably PSU.

I definitely would not recommend doing this. A new PSU that can properly fuel that card would set you down only $40-50 for a low end one.

tl;dr don't be retarded

 

Well it may not even start up at all for one, and you'd be essentially "strangling" your PC components as they're not getting all the power they need. Your PSU would be overloaded so it would probably explode at some point also...

Get a good quality PSU with enough wattage for your needs, you're saving yourself a lot of stress (and a lot of breakages).

 

a 750ti should be plug n play with prebuilts, what are your specs? 300 should be fine but yeah what blupig said, it's retarded to have a shitty PSU.

Edit: http://amzn.com/B00H33SDR4 here's a cheap PSU